Building Energy Ratings

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Lorcán Mooney

designing

e: lorcan.mooney@pmg.ie

BUILDING SERVICES you cannot control what you do not measure — building energy ratings (ber) Under Ireland’s latest regulations, with increased costs and growing environmental concerns, energy efficiency has never been higher on the business agenda. Any business looking to its future competitiveness is looking at energy efficiency. Both business and Government are now making energy efficiency a core strategic imperative and recognising that there is a new energy future. Those ready to take action by measuring and benchmarking their consumption are seeing the benefits – real cost savings and real environmental gains. On one particular development Project Management Group has succeeded in reducing a client’s energy consumption by 37%(1). In this article we look at some of the key issues and success factors associated with Ireland’s response to the European Performance Building Directive (EPBD), and with Building Energy Rating (BER) certificates which measure and benchmark domestic and commercial buildings’ energy consumption. The EU Directive on the Energy Performance of Buildings (EPBD) contains a range of provisions aimed at improving energy performance of residential and

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an objective scale of comparison for the energy performance of a building ranging from A1 to G. Similar to the A to G rating for a household electrical appliance on fridges and washing machines, A-rated homes are the most energy efficient and G-rated the least efficient. The BER is intended to give prospective buyers, occupants and tenants information about the energy performance of the building. The BER also gives builders, developers, vendors and landlords an incentive to upgrade the energy Figure 1 shows a domestic BER energy label. Image courtesy of SEI

non-residential buildings, both new-build and existing. This Directive was adopted into Irish law in 2006 with SI 666. A Building Energy Rating (BER) certificate is part of Ireland’s response to the EPBD Directive. The EPBD also covers a wide range of other elements, including mandatory inspection of boilers and air-conditioning systems. A BER is effectively an energy label. A domestic BER label is shown in Figure 1 and a non-domestic label in Figure 2. Building Energy Rating (BER) A Building Energy Rating (BER) is

Figure 2 shows a non-domestic BER energy label. Image courtesy of SEI

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you cannot control what you do not measure — building energy ratings (ber) performance of the building by giving visible credit to superior standards. A BER certificate is valid for 10 years. Building Energy Rating Audit A BER audit will measure the energy performance of a building, taking into account features such as:— — Size of the building; — Fabric of the building, uvalues, etc; — Amount and type of glazing; — Water heating system; — Space heating system; — Renewable energy sources, if present. To calculate a rating, an assessment of the building must be performed through an SEIaccredited software package — DEAP for domestic dwellings and NEAP for non-domestic dwellings. BERs have to be carried out by specially-trained BER assessors, registered by Sustainable Energy Ireland (SEI). A list of domestic BER Assessors is currently available on the SEI website and the list for existing dwellings and non-domestic dwellings will be available shortly. BER assessors (usually building professionals like engineers, etc) must have successfully completed a certified training programme that meets the requirement of a Training Specification which was published in October 2006. The BER must also be accompanied by an Advisory Report setting out recommendations for costeffective improvements to the energy performance of the building. However, there will be no legal obligation on vendors or

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prospective purchasers to carry out the recommended improvements. The Advisory Report will contain information as to the efficient operation of the building, as well as the recommendation of any remedial measures to the building fabric or fittings that will improve the overall energy efficiency of the building. An Advisory Report may contain additional advice on the following areas:— — Insulation — Glazing; — Heating Systems; — Heating Controls; — Lighting and Appliances; — Renewable Energy Sources, (eg, combined heat and power generation, solar, wind, geothermal, wood pellets, etc) BER Software DEAP – Domestic Energy Assessment Program — is currently only applicable for new dwellings. The DEAP software and advisory report system is currently being revised to accommodate existing dwellings and the existing dwelling survey methodology is currently being drafted within SEI. NEAP – Non-Domestic Energy Assessment Procedure — is the methodology for demonstrating compliance with specific aspects of Part L of the Building Regulations. For all other buildings other than dwellings NEAP will also be used to generate the BER and Advisory Report for new and existing nondomestic buildings.

NEAP calculates the energy consumption and CO2 emissions associated with a standardised use of a building. The energy consumption is expressed in terms of kilowatt hours per square metre floor area per year (kWh/m2/yr), and the CO2 emissions expressed in terms of kilograms of CO2 per square metre floor area per year (kg CO2/m2/yr). NEAP’s default calculation tool is SBEM (Simplified Building Energy Model) which is based on CEN standards that have been developed by BRE on behalf of the UK Department of Communities and Local Government. It calculates monthly energy use and carbon dioxide emissions of a building given a description of the building geometry, construction, use and HVAC and lighting equipment. SBEM was originally based on the Dutch methodology NEN 2916:1998 (Energy Performance of Non-Residential Buildings) and has since been modified to comply with the emerging CEN Standards. SBEM calculates the consumption and iSBEM benchmarks the building and generates an energy label. Although DEAP and NEAP (SBEM) may assist in the design process, they are not considered primary design tools. Exemptions The following buildings are exempt from the BER scheme:— — Listed national monuments; — Listed buildings of outstanding architecture or

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bs news by Design 15

12/12/08

12:32 PM

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you cannot control what you do not measure — building energy ratings (ber) — — —

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historic importance (known as protected structures); Buildings used as places of worship or for the religious activities of any religion; Certain classes of temporary buildings such as site offices; Industrial buildings not intended for human occupancy over extended periods and where the installed heating capacity does not exceed 10W/m2; Non-residential agricultural buildings with low energy demand; Small stand-alone buildings with a total useful floor area of less than 50m2.

There are exemptions for certain categories of buildings, eg, protected structures and certain temporary building(2). BER Implementation Dates A BER certificate will be required at the point of sale or rental of a building, or on completion of a new building. Implementation

schedule for the regulations was set out as follows: — Domestic — All new domestic dwellings from July 2008; — All new and existing domestic dwellings from the January 2009. Non-Domestic — All new non-domestic from July 2008; — All new and existing nondomestic from the January 2009. Implications of non-compliance There are fines of up to e5,000, or a term of imprisonment not exceeding three months, for non-compliance with the regulations(2) Conclusion A recent study commissioned by SEI(3) estimates that the commercial sector could save up to 25% of its current energy use through investment in

economically-viable efficiency opportunities, hence indicating the value by measuring and benchmarking a building’s energy consumption. The benefits associated with purchasing or constructing a new building that has a high BER are numerous in both the long and short-term. These include:— — Improved corporate profile; — Coherent energy strategy; — Reduced carbon consumption; — Increased comfort levels; — Reduced running costs; — Better for the environment; — Maximising resale value; — Future-proofing property. Obtaining the maximum BER for a new building need not be a very expensive process if it is carefully planned (i.e., reducing the design infiltration rate from 10 to 5mcu/hr/msq @ 50Pa); and if it is incorporated into the building design and specification as early as possible in the design and construction phases. Bibliography Lorcán Mooney is a Lead Environmental Project Engineer with Project Management Group (PMG). As well as being passionate about the Environment, he has a BEng in Mechanical Engineering and a Pg.Dip in Project Management. PMG is Ireland’s largest full service A&E firm, providing professional services in project and construction management, architectural and engineering design, and technical consultancy

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References (1) Project Management Group (2) SI No: 666 of 2006 (3) Energy in Business (SEI Study)

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